Contours (10m): Offshore of Tomales Point, California, 2010

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Abstract/Contents

Abstract
This line shapefile contains bathymetric contours at 10 meter intervals for the offshore area of Tomales Point, California. This layer was generated from bathymetry data collected by Fugro Pelagos and California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB) and by the U.S. Geological Survey. Mapping was completed between 2004 and 2010, using a combination of 200-kHz and 400-kHz Reson 7125, and 244-kHz Reson 8101 multibeam echosounders, as well as 234-kHz and 468-kHz SEA SWATHPlus phase-differencing sidescan sonars. These mapping missions combined to collect bathymetry from about the 10-m isobath to beyond the 3-nautical-mile limit of Californiaís State Waters. Bathymetric contours at 10-m intervals were generated from a modified 2-m bathymetric surface. The original surface was smoothed using the Focal Mean tool in ArcGIS and a circular neighborhood with a radius of 20 to 30 meters (depending on the area). The contours were generated from this smoothed surface using the ArcGIS Spatial Analyst Contour tool. The most continuous contour segments were preserved while smaller segments and isolated island polygons were excluded from the final output. The contours were then clipped to the boundary of the map area. A map that shows these data is published in Open-File Report 2015-1088, "California State Waters Map Series--Offshore of Tomales Point, California." This layer is part of USGS Data Series 781.
Purpose
In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. Part of the marine habitat mapping data for the California North Central Coast Mapping Project (NCCMP), this coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information.

Description

Type of resource cartographic, software, multimedia
Form Shapefile
Extent 0.602
Place Santa Cruz, California, US
Publisher Geological Survey (U.S.)
Date valid 2004 - 2010
Publication date 2015
Edition Version 1.0
Language English
Digital origin born digital
Map data Scale not given. ; Custom projection W 123°4ʹ30ʺ--W 122°53ʹ42ʺ/N 38°15ʹ19ʺ--N 38°5ʹ45ʺW 123°4ʹ30ʺ--W 122°53ʹ43ʺ/N 38°15ʹ19ʺ--N 38°5ʹ45ʺ, Scale not given ; EPSG::4326

Creators/Contributors

Creator Kvitek, Rikk G.
Creator Dartnell, Peter
Creator Pacific Coastal and Marine Science Center
Creator Seafloor Mapping Lab
Creator Golden, Nadine E.

Subjects

Subject Coasts
Subject Contours (Cartography)
Subject Ocean bottom
Subject California
Subject Marin County (Calif.)
Subject Pacific Ocean
Subject Tomales Bay (Calif.)
Subject 2004-2010
Subject Geoscientific Information
Subject Oceans
Subject Elevation
Genre Geospatial data
Genre Cartographic dataset

Bibliographic information

WGS84 Cartographics This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
Location https://purl.stanford.edu/rt793kd9427

Access conditions

Use and reproduction
This item is in the public domain. There are no restrictions on use.
Copyright
This work is in the Public Domain, meaning that it is not subject to copyright.

Preferred citation

Preferred citation
Dartnell, P., Kvitek, R.G., and Bretz, C.K. (2014). Contours (10m): Offshore of Tomales Point, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/rt793kd9427.

Collection

California State Waters Map Series Data Catalog

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